import math
cnt=0
days=[31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
for m in range(1,13):
    for d in range(1,days[m-1]):
        if m == math.floor(d/10)+(d-math.floor(d/10)*10):
            cnt+=1
print(cnt)